1. Field of the Invention
The present invention relates to the exchange of data between computers and removable digital data storage media such as optical disks. More particularly, the invention concerns a plugable media stackloader apparatus that can be plugged into a slot of a host computer for processing media in a drive of the host computer. Another aspect of the invention concerns a process for operating the stackloader and the host computer to manage, maintain, and utilize storage media of the stackloader.
2. Description of the Related Art
To store large amounts of data under conditions guaranteeing automatic, reasonably speedy access to data storage media, media libraries have been developed. These libraries store the media in magazines and employ transport mechanisms to move media instances between magazines and media drives.
Magazines containing media, such as cartridges which contain optical or magnetic disks, are presently processed by large and complex transport systems. An operator inserts a magazine into a receptacle which positions cartridges in the magazine for processing. A picker transports a selected cartridge from the magazine to a drive where a disk contained in the cartridge is processed by writing and reading data on the disk. After processing, the cartridge is transported to the magazine and the picker stands ready to transport another cartridge. The picker for such a transport system is somewhat complex. The picker grabs and withdraws the cartridge from the magazine in an X direction, transports it in a Z direction and inserts the cartridge in the drive in the X direction. Normally the picker includes a receptacle through which the cartridge is translated between the magazine and the drive without any flipping of the cartridge.
There has been a long standing and strong felt need in small, low-end computer systems for a media storage and transport system that provides a magazine mounted library capability without requiring additional drive or a standalone library. What has been described hereinabove is a large system employed by companies or other entities which have a large volume of data to be processed. Such a system is too large and too expensive for a small system which processes data on a personal computer. It is obvious that the scheme of the large system is not applicable for processing magazine mounted media by a personal computer. To be compatible with a personal computer the apparatus must be small, easy to use and low in cost.
In small computer systems, stackloaders have been developed to provide library-like services for media such as tape or floppy disks. Stackloaders typically store a plurality of medium instances (such as tape cassettes) in a vertical array (a "stack") by means of a frame, which may be plugged into a medium drive receptacle. A transport mechanism selects a medium instance, extracts it from the stack, loads it into the drive, and later extracts it from the drive and returns it to the stack.
To date, stackloaders for small computer systems have been particularly adapted for a single use. Relatedly, no stackloader is known which can either plug into a drive receptacle or operate on a standalone basis. Further, the existing stackloaders are not capable of accessing medium instances in adjacent receptacles. Last, known stackloaders are designed for use with particular medium configurations and cannot adapt to the different distances and dimensions of other configurations. Thus, there is a manifest need for a stackloader that can interface with a small computer system by anchoring in a drive receptacle, yet which can store medium instances and operate outside of the drive receptacle and access medium instances in adjacent drive receptacles. The need also embraces the as-yet unsatisfied requirement that the stackloader be adaptively reconfigurable to the dimensions and distances of different medium configurations.